This invention relates to manual transmission clutches for automotive vehicles and more particularly to a modular friction clutch unit which is pre-assembled and balanced off line for installation on manual transmission equipped cars produced on a common production line in an interchangeable manner with the remaining cars being equipped with automatic transmissions.
In current vehicle assembly plant operations a first attaching arrangement is required to install an automatic transmission torque converter on the engine crankshaft of an automatic drive vehicle and a second attaching arrangement is required to install a manual transmission friction clutch on an engine crankshaft of a manual drive vehicle. The U.S. Pat. No. 4,586,401 issued May 6, 1986 to T. D. Nogle discloses a vehicle automatic transmission torque converter having its drive plate connected to the engine crankshaft so as to be piloted therefrom in a conventional manner.
An example of a conventional mounting arrangement currently used in vehicle assembly plants for installing a manual transmission friction clutch on an engine crankshaft is disclosed in prior art FIG. 1. FIG. 1 shows a current production friction clutch assembly 10', located within a manual transmission housing 11', having a flywheel 12' connected to and rotatably driven by a prime mover such as an automotive engine (not shown). The flywheel 12' is mounted on the output end of an engine crankshaft 13' by means of a radial collar 14' formed thereon. A plurality of machine bolts 15' are arranged in a circle about transmission and clutch axis A' coaxial with the crankshaft axis of revolution 16' with the bolts 15' extending through associated circumferentially distributed flywheel holes 17' for engagement in aligned threaded collar bores 18'.
The clutch assembly 10' comprises a clutch cover and pressure plate assembly 20', a disc assembly 22', and the flywheel 12'. The clutch cover and pressure plate assembly 20' includes a clutch cover 24', suitably secured to the flywheel 12' such as by circumferentially distributed bolts 25', and carries pivot ring retaining studs 26' which are arranged in a circle about the clutch axis A'. The clutch cover and pressure plate assembly 20' further includes a diaphragm spring 27' provided with a first pivot ring 28', held by the heads of rivets 29' and a second identical pivot ring 30' held between the diaphragm spring 27' and the clutch cover 24'.
The diaphragm spring 27' includes a central portion, fragmented into radially inwardly projecting spring fingers, partially indicated at 32', a radially outermost main spring section 34' which normally bears against adjacent projections 36' of pressure plate 38' and the spring fingers 32'.
As seen in prior art FIG. 2 the cover assembly 20' is axially movably secured to cover base 24' by a set of substantially tangentially extending leaf springs strips 40' with each set secured at one end to the pressure plate 38' by rivet 41' and secured at the opposite end to the clutch cover 24' by rivet 42'. The leaf spring strips 40' allow for a limited axial movement of the pressure plate 38' while permitting the transfer of torque between the clutch cover 24' and the pressure plate 38'. The pressure plate 38' is normally biased against the adjacent one friction lining 44' of the disc assembly 22' by the diaphragm spring radially outermost main section 34' which normally bears against the adjacent projections 36' of the pressure plate 38'. The other friction lining 46' of the friction clutch disc assembly 22' then bears against the flywheel 12' and transmits torque to the transmission input shaft 48' through the medium of a hub 50' having internal splines 52' extending into complementary external splines 54' on the output shaft 48'. The fingers 32' can be engaged and shifted in the axial direction toward the flywheel 12' by a suitable thrust bearing 56'. At such time, the diaphragm main section spring 34' is tilted between the two pivot rings 28' and 30' in a conventional manner. It will be noted in FIG. 1 that starter ring gear 58' is suitably fixed to the flywheel 12' in a concentric manner relative to clutch axis "A" and crankshaft blind bore 84' by being seated in outer annular flywheel notched-out shoulder 60'.